Cable equalizer



Nov. 21, 1939.

I. J. WILSON CABLE EQUALIZER Filed March 11, 1938 2 SheetsSheet 1 INVENTOR.

v ATTORNEYS.

Nov. 21, 1939. 2,180,491

CABLE EQUALIZER Filed March 11, 1938 2 Sheets-Sheet 2 i I f INVENTOR.

BY 6 Maw/m I A TTORNEYS;

Patented Nov. 21, 1939 rarest @FFiQE i CABLE EQUALIZER Thomas I. Wilson, Pittsburgh, Pa, assignor to Hydraulic Equalizer Company, a corporation of Pennsylvania Application March ll,

5 Claims.

My invention relates to cable equalizers; that is, to apparatus for equalizing, tension ina plurality of cooperating load-sustaining cables. More particularly the invention is directed to cable equalizers for elevators. 1

In United States Patent No. 2,001,007, granted May 14,1935, on my application, I illustrate, and. describe a cable equalizer which has proved very eliicient in, service. My present invention con.- sists in refinements and elaborations of the patented structure.

The apparatus of such patent is particularly adapted for service in elevator installations in which the endsof the cables are secured to the tops of the elevator cages, while the apparatus of my present invention is particularly designed for service in installations in which the ends of the elevator cables are anchored to the structural framework at the tops of the elevator shafts.

In the accompanying drawings Fig. I is a view in perspective of an, apparatus embodying the invention; and Fig-II is a fragmentary View, showing portions of the apparatus to larger scale and partly in side elevation and partly in vertical section.

It will be understood that, while this invention is particularly directed to elevator installations in which the lifting cables are anchored at the top of the elevator shaft, the apparatus of the invention embodies structural refinements that will prove valuable in installations in which one end of eachliiting cable is anchored to the top ofthe elevator cage.

Referring to Fig. I of the drawings, the horiu, zontal beams B, B are members of the usual structural steel framework at the head of an elevator shaft, and in usual practice it is to these beams that the ends of the cables that sustain the cage are secured, by means of known cableanchoring structure. In accordance with this invention, I dispense with the usual cable-anchoring structure, and on a load-plate P on the beams B, B I mount my equalizing apparatus E and secure it, say by Welding or bymeans of through bolts 2. As will appear in the ensuing specification, the ends of the cables are anchored in the equalizing apparatus.

The equalizing apparatus includes: (1) a plurality of pistons that are severally movable in cylinders which communicate in common with a confined body of fluid, preferably liquid; (2) a plurality of movable members, and (3) a plurality of stress-transmitting members severally interconnecting the movable members with the pistons. The elevator cables are severally connected to the movable members in such manner that the stresses effective on the cables are transmitted to the pistons .acting on the confined body of liquid. When the load is unequally distributed amongthe several cables, the pistons that sustain 1938, Serial No. 195,284

the stresses of the overloaded cables move inward, displacing liquid from their cylinders and forcing the displaced liquid in proportionedquantities into the cylinders whose pistons are under less stress. Thus, in accordance with known hydraulic laws, the several pistons, operating in cylinders of uniform diameter, are automatically adjusted and maintained in such positions that not only is the total hydraulic force effective on the pistons equal andopposite in direction to the tension on. the load-sustaining cables, but the tension is uniformly distributed among the several cables.

The confined body of liquid consists in a body of light oil 20 (Fig. II) enclosed in a metal casing lll; the pistons acting on the body of liquid consist in double-cup-Washer pistons l2, severally. arranged in cylinders ll of equal diameter; the movable members to which theelevator cables, (35) are connected (indirectly connected in this case) consist in levers 29; and the stress-transmitting members that interconnect the movable members and the pistons consist in plunger rods l3 that extend throughplunger-aligning bushings l4 in the casing l0 and carry the pistons l2 at their inner or lower ends. Each cylinder II is half filled, (more or less) with the liquid (20) and communication between the several cylinders is established through passages I6 and IT. The liquid within the said cylinders and passages comprises the confined body of liquid mentioned above, audit will be noted that I provide a normally closed inlet 4 and outlet '5, by'means of which liquid may be introduced to or removed from the internal system of cylinders and passages, as the need therefor arises in service.

More specifically, the levers 29. provide angularly movable members which in this case are severally pivoted intermediate their opposite ends in the bifurcated upper ends of standards 24, and the elevator cables 33 are severally connected to the levers 29 through levers 29a and connecting rods 29?). The levers 2911 are pivotally secured intermediate their ends in the bifurcated lower ends of standards 24; the ends of the cables 33 are severally connected to the inner ends of levers 29a, and the connecting rods 29b. pivotally interconnect the outer ends of the levers 29a with the outer ends of levers 29. It may be mentioned that each pair of standards 24, 24' is shown as. formed of two bars of steel (Fig. II), extending one upward and one downward and secured to the load-plate P. The upper bar extends downward through the wall of casing l0 and bears at its lower end upon the top-of the load-plate. A bolt or screw 6 secures the bar in such position. The lower bar bears against the bottom of the, load-plate and is made rigid therewith, by means. of a threaded shank filland nuts 6|; Asshown, hetwobarsiiomiina heistandardfl; 3.4- re n axially aligned, but it is to be understood that the standard may be formed of single length of bar-steel, extending vertically through the casing l and rigidly riveted, welded, or bolted to the load-plate.

The inner ends of the levers 29 are severally connected to the outer ends of the plunger rods I3, and advantageously the connections are effected by means of links 3. The links are pivotally secured at their upper ends to the levers and at their lower ends to the plunger rods; the connection is mechanically secure and positive in operation; there is freedom from lost motion and play between the parts; there is no sliding engagement between the parts, and wear is minimized. When in service the levers move angularly, the plunger rods move axially, and in making accommodation for such movements the links 3 move in a direction which is at once both angular and linear.

In service the load on the elevator cables is effective in vertical direction, on the inner ends of levers 29a, as indicated by the arrows in Fig. I, and manifestly the stresses exerted by such load are transmitted through the levers 29a, rods 2%, levers 29 and links 3, to the plunger rods l3. Each rod l3 transmits the downwardly directed stress or thrust to its piston l2, and the piston in turn exerts pressure on the confined body of liquid 20.

The body of liquid, being incompressible, opposes and prevents the downward or inward movement of the pistons when the stresses in the several plunger rods 43 are equalized, and, obviously, the stresses in the plunger rods are equal only when the stresses in the several cables 33 are equalized. If in service the load on the cables becomes unequally distributed, the pistons within the hydraulic cylinders ii are automatically adjusted, in accordance with known hydraulic laws, into such positions that load on the cables is equalized.

Provision is made to safeguard the apparatus in the event that the supply of liquid confined in the system of cylinders H and passages I6, I! fails or becomes inadequate. More particularly, the base of the slot in the upper end of each standard 24 is formed to provide an inclined surface 24a. This surface provides a positive stop.

. Upon failure of liquid each lever 29 will swing in plunger-depressing direction until the lower edge of the lever comes to position against the stop 24a formed in its supporting standard 24. All levers are arrested in this way. The lever can swing no further under the stress transmitted from the cables, and the apparatus functions as the usual rigid cable-anchoring devices.

If one of the cables should break in service, the corresponding plunger l3 will, manifestly, move upward under the pressure of the fluid which is still subject to compression by the other plungers. The rising plunger rod will swing the lever 29 until its lower edge comes to abutment upon an inclined surface 24b formed at the base of the slot in its standard 24. Thus, the apparatus will continue to function properly with the cables that remain sound.

It will be perceived that the structure is compact, with all parts arranged symmetrically of the vertical mid-plane of the casing ill. And it will be understood that within the terms of the appended claims, various modifications and refinements are permissive.

I claim as my invention:

1. In equalizer apparatus including a plurality of hydraulic pressure units in common hydraulic communication, and means for transmitting severally to such units the stresses of a plurality of cables under tension; the refinements herein described in which said means include a plurality of angularly movable members arranged at the top of said apparatus and connected, at points spaced from their centers of turning, severally to said pressure units, and a corresponding plurality of angularly movable members arranged at the bottom of said apparatus, said last-mentioned members providing, at points spaced from their centers of turning, means for severally securing the ends of said cables, and means severally interconnecting said angularly movable members for movement in pairs, each of which includes one of. said angularly movable members at the top of the apparatus and one of the angularly movable members at the bottom of the apparatus, whereby the tension stresses in said cables are resolved into compressive stresses effective upon said hydraulic units and equalized.

2. In equalizer apparatus including a plurality of hydraulic pressure units in common hydraulic communication, and means for transmitting severally to such units the stresses of a plurality of cables under tension; the refinements herein described in which said means include a plurality of angularly movable members arranged at the top of said apparatus, links severally connecting said members, at points spaced from their centers of angular movement, to said pressure units, and a corresponding plurality of angularly movable members arranged at the bottom of said apparatus, said last-mentioned members providing, at

points spaced from the centers of turning, means for severally securing the ends of said cables, and means severally interconnecting said angularly movable members for movement in pairs, each of which includes one of said angularly movable members at the top of the apparatus and one of the angularly movable members at the bottom of the apparatus, whereby the tension stresses in said cables are resolved into compressive stresses effective upon said hydraulic units and equalized. 3. In equalizer apparatus comprising a block including a plurality of hydraulic cylinders in communication with one another, plungers in said cylinders, a set of levers pivotally mounted adjacent to the top of said block and severally connected, at points spaced from their centers of turning, to said plungers; the refinement herein described that consists in a second set of levers pivot-ally mounted below said block and adapted severally to secure, at points spaced from their centers of turning, the ends of a plurality of cables under tension, and vertically reciprocable rods severally interconnecting the levers in the lower set with the levers in the upper set, whereby the tension stresses of said cables severally are resolved into compressive stresses effective on said plungers and equalized, substantially as described.

4. The structure of. claim 3, in which said ap-' paratus includes two sets of supports integrated to and extending one set above and the other 

